1. Field of the Invention
The present invention relates generally to a method for detecting the specificity of activated lymphocyte. More particularly, the present invention relates to a method for detecting the specificity of activated lymphocyte in vivo after transplantation, virus/bacteria infection, or vaccination.
2. Description of the Prior Art
Immune or immunity is a physiological response for biological recognition and clearance of foreign antigens (pathogens). Most antigens are not autologous, but from exogenous sources (foreign antigen). After entering the body, foreign antigens will be recognized and eliminated promptly through a series of immune responses initiated by the immune system of the body.
During transplantation, the antigenicity differences between donor and recipient, such as the differences between major histocompatibility antigen (MHC) and Minor histocompatibility antigen (mH-antigen), can induce the recipient to produce specific activated lymphocytes targeting antigens, which are present in the organ/tissue from donor and are different from those antigens from recipient. The lymphocytes thus produced will then attack the organ being transplanted, resulting in rejection reaction. Specific activated lymphocytes targeting different pathogens can also be produced when body is stimulated/infected by pathogenic microorganisms such as measles virus, respiratory syncytial virus, hepatitis A virus, hepatitis B virus, hepatitis C virus, hepatitis E and F virus, chickenpox and herpes zoster virus, herpes simplex virus, cytomegalovirus, EB virus, coronavirus, rotavirus, Coxsackie virus, ECHO virus, Ebola virus, Yellow fever virus, Adenovirus, forest encephalitis, Rubella virus, Dengue fever virus, epidemic encephalitis B virus, Rabies virus, SARS virus, Influenza virus (include human and birds), epidemic mumps virus, hemorrhagic fever virus, HIV, poliomyelitis virus, Rickettsia, epidemic encephalitis diplococcus, Bacillus typhi or Bacillus paratyphosus, Mycobacterium tuberculosis, Bacillus diphtheriae, Bordetella pertussis, Bacillus anthracis, Bacterium burgeri, Yersinia pestis, Lepra bacillus, atypical Mycobacterium, Leptospire, Treponema pallidum, Spirochaeta recurrentis, Chlamydia, Cyptozoite, Leishmania, Toxoplasma, Schistosome, Paragonimiasis, Chinese liver fluke, Fasciolopsis, Filaria, etc. A variety of specific activated lymphocytes targeting various antigens can exit in the same body, for instance, to a patient who suffered rejection and was infected by herpes virus after heart transplantation, his body will generate both specific activated lymphocytes against MHC and mH-antigen of the donor organ and specific activated lymphocytes against herpes virus.
Transplantation is the last hope in the end-stage treatment selections for many organs. After transplantation, the differences in MHC and mH-antigen between donor and recipient always give rise to rejection, which remains a major cause of mortality at 3, 5, and 10 years after organ transplantation such as heart, liver, kidney and marrow transplantation, as well as cellular transplantation, and rejection starts from lymphocytes activation. The presence of anti-donor specific activated lymphocytes in the recipient generally indicates body has initiated or is initiating attacks on donor organ. Accordingly, appropriate measure, such as increasing the dosage of the immunosuppressive agent used or changing to another type of immunosuppressive agent, should be adopted promptly to make the transplanted organ function normally in the recipient, so as to improve the life quality and life span of the recipient.
Biopsy, which is an invasive method and can not be repeated daily, is the current golden standard for rejection diagnosis worldwide. This method, however, has not been widely accepted by doctors and patients because it causes painful experience, and it is dangerous and expensive. Furthermore, because foci severities only exit in certain parts of an organ, and biopsy sample can be only taken from a certain part of the organ, the misdiagnosis rate can be high; In addition, the purpose of biopsy is to detect pathological changes, thus, the discovery of pathological changes actually indicates organ has been damaged already. Therefore, what is needed is to provide a non-invasive diagnostic method, which is fast, convenient, and has high sensitivities to rejection reaction to improve the life quality of organ recipient and the life span of the organ transplanted. Rejection starts as the activation of lymphocytes, therefore, activated lymphocytes should exist prior to pathological changes. Accordingly, the present invention is designed to diagnose rejection reaction through the detection of specific lymphocytes activated by MHC or mH antigen in peripheral blood. As a result, the method provided in the present invention can diagnose rejection reaction well before pathological changes occur in transplanted organ. Additionally, the method provided herein is easy to carry out, easy to be standardized, and can be converted to automatic operation. Moreover, the method can overcome the defects in biopsy assay and provide quick, accurate and definite diagnostic result for rejection reactions. The method can be used as a guidance for dose usage of immunosuppressive agent in clinic. The method can also be used to improve the life quality of patients and extend the life span of implant.
Many pathogenic microorganisms such as measles virus, chickenpox virus, epidemic encephalitis B virus, and Mycobacterium tuberculosis etc. have a latent period before occurrence of diseases, during which the symptoms are generally atypical such as fever etc. The diagnosis of the diseases caused by these pathogens, however, generally depends on the diagnosis of typical symptoms (specific symptoms), the occurrence of which is always delayed in such diseases due to the latent period. As a result, the misdiagnosis rate can be high.
The present invention can also be used to diagnose the infection of pathogenic microorganism. It provides an accurate and quick method to detect diseases in the latent period and early stage. Accordingly, it will be significant to realize the goals of early to detect, early to quarantine, early to treat, and reducing infection rate.